Search found 29 matches

by korzen303
Wed Jun 24, 2020 10:35 am
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Damping in XPBD
Replies: 0
Views: 1124

Damping in XPBD

Hello, I am working on a surgical simulator using XPBD. I am trying to implement a better damping as currently with simple viscous damping the virtual anatomy is either unresponsive or oscillates too much. I have adapted the solveDistVel() method from this repo https://github.com/matthias-research/p...
by korzen303
Fri Aug 26, 2016 11:24 am
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Applying custom position based constraints in physics engine
Replies: 1
Views: 3278

Re: Applying custom position based constraints in physics en

OK, I solved this by storing the position from the previous time-step and treating the current position as a predicted one. Seems to work OK, but it is oscillating much more than the standard PBD. And the collisions also often eject rod particles too much. This is probably due to partial overwriting...
by korzen303
Fri Aug 26, 2016 9:01 am
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Applying custom position based constraints in physics engine
Replies: 1
Views: 3278

Applying custom position based constraints in physics engine

Hi, I need to apply my custom position based constraints (for elastic rod) on a chain of rigidbodies in Unity, which uses PhysX underneath (but the problem concerns any physics engine really). To keep things simple let say that I want to apply a simple distance constraint between positions of two ri...
by korzen303
Sun Jul 17, 2016 2:55 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Position and Orientation Based Cosserat Rods
Replies: 1
Views: 4188

Position and Orientation Based Cosserat Rods

Hi Guys, I am trying to implement this paper: http://www.cg.informatik.uni-mainz.de/files/2016/06/Position-and-Orientation-Based-Cosserat-Rods.pdf I have got the position based rod simulation framework implemented but I got stuck on the constraints. http://i64.tinypic.com/10hrfbp.jpg In eq. 37 for t...
by korzen303
Sun Jul 17, 2016 7:37 am
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: [SOLVED] Position Based Elastic Rods implementation
Replies: 32
Views: 19335

Re: [SOLVED] Position Based Elastic Rods implementation

Hi Guys, there is a new paper on this entitled "Position and Orientation Based Cosserat Rods". It is very similar to PBER but x10 faster. http://www.cg.informatik.uni-mainz.de/people/tassilo-kugelstadt-m-sc/position-and-orientation-based-cosserat-rods/ Will give it a go and try to implement it this ...
by korzen303
Tue Jan 12, 2016 6:11 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: [SOLVED] Position Based Elastic Rods implementation
Replies: 32
Views: 19335

Re: [SOLVED] Position Based Elastic Rods implementation

I did not have time to optimize the code. From a quick comparison it seems that nearly direct port to Eigen is 5-10 times (!) slower than the original implementation by Serphertoh. This is most likely because the lack of vectorization on Eigen's Vector3f and Matrix3f structures (I don't know why PBD...
by korzen303
Mon Jan 11, 2016 11:05 am
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Position-based Elastic Rod
Replies: 10
Views: 12788

Re: Position-based Elastic Rod

In case someone needs a working code for the Position Based Elastic Rods check this post:
http://bulletphysics.org/Bullet/phpBB3/ ... 93&p=36852
and the sources are here:
https://github.com/korzen/PositionBased ... ElasticRod
by korzen303
Mon Jan 11, 2016 11:02 am
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: [SOLVED] Position Based Elastic Rods implementation
Replies: 32
Views: 19335

Re: [SOLVED] Position Based Elastic Rods implementation

Good to hear that. I have made a fix in CMake files to turn the OpenMP off by default.
by korzen303
Mon Jan 11, 2016 8:06 am
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: [SOLVED] Position Based Elastic Rods implementation
Replies: 32
Views: 19335

Re: [SOLVED] Position Based Elastic Rods implementation

Check the readMe file in Demos/ElasticRodDemo:

"IMPORTANT: The OpenMP is not supported in this release!
By default, the CMake generated ElasticRodDemo project has OpenMP turned on.
Deactivate it to run the demo, otherwise to rod will explode."

Sorry for the inconvenience
by korzen303
Fri Jan 08, 2016 2:32 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: [SOLVED] Position Based Elastic Rods implementation
Replies: 32
Views: 19335

Re: Position Based Elastic Rods implementation

I have made an implementation for PBD library. It is basically a rough and dirty port of Serpherot's code to Eigen. I will need to spend some more time on matrix ops optimizations. Very likely that his implementation is much faster. The repo is here. I have asked Jan to pull it into PBD main branch....
by korzen303
Fri Jan 08, 2016 2:32 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: [SOLVED] Position Based Elastic Rods implementation
Replies: 32
Views: 19335

Re: Position Based Elastic Rods implementation

There was a couple of minor bugs. The main thing was to change the indices when computing the Darboux Vector (not entirely sure why). Again, credits to Serpheroth:
const int permutation[3][3] =
{
//0, 1, 2,
//1, 2, 0,
//2, 1, 0
0, 2, 1,
1, 0, 2,
2, 1, 0
};
by korzen303
Wed Jan 06, 2016 6:14 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: [SOLVED] Position Based Elastic Rods implementation
Replies: 32
Views: 19335

Re: Position Based Elastic Rods implementation

https://bitbucket.org/yukikoyama/view-d ... on-for-3d/ have found an old repo from the original author. Hope this will help. This is a different paper (except that the first author is also Japanese). But thanks Mobeen anyway, they also use some sort of elastic rod using PBD and oriented particles [...
by korzen303
Wed Jan 06, 2016 11:46 am
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: [SOLVED] Position Based Elastic Rods implementation
Replies: 32
Views: 19335

Re: Position Based Elastic Rods implementation

The zip files contain only the readMe file, similarly as the GitHub repo. Anyways, I have managed to solve the problem. Will update the source files soon.